Relay.



J. T. DEMPSTER.

RELAY.

APPLICATION HLED JUNE 24.1916.

Patented Mar. 27, 1917.

Witnesses UNITED STATES PATENT OFFICE.

Ion TH. D, 01' SCHIIICTADY, m YORK, MIDI 1'0 Gm MIC A OOlPOl-ATIOI OI I117 I011.

may. 7

1,220,826, hesitation 1mm hunt Patented Mar. 27, 1917. Application mama 24, mu. m Io. m,

To all whom it may concern: function of the rate of flow of current in Be it known that I, JOHN T. Dmarsm, a subject of the King of Great Britain, residing at Schenectad in the county of Schenectady, State of Jew York, have invented certain new and useful Improvements in Relays, of which the following is a specification.

M invention relates to relays and particularly to relays desi ed to protect apparatus included in ane ectrical installation from the injurious effects of overloads and similar abnormal disturbances. More specifically my invention relates to inverse time I limit relays to be used in protective devices for electrical apparatus.

The object of my invention is to provide a novel and improved construction of relay, and in particular a novel construction of inverse time limit relay. A further object of my invention is to provide a relay for protective devices which has a pronounced and emphasized inverse time limit characteristic, and which'is simple in construction and accurate in operation.

The features of'my invention which I believe to be novel and patentable are definitely indicated in the claims appended hereto. The details of construction and mode of operation of an inverse time limit relay embodying the features of my invention will be understood ,from the following description taken in connection with the accompanying drawings, in which:

The figure is a diagrammatic view in perspective of a relay embodying my invention and operatively connected to a circuit breaker in an electrical installation.

In the accompanying drawings, I have illustrated the relay of my invention operatively related to a circuit breaking device 5 arranged in an electrical installation 6 for the protection of the translating devices 7. The vcircuit breaking device 5 is of the usual construction and is responsive to an electromagnet coil 8 included in an electric circuit 9. When the electric circuit 9 is completed, the coil 8 is energized. The circuit breaker is thereupon tripped in the usual manner, and the flow of current in the installation interrupted.

Two movable contact members are included in the electric circuit 9. One of these contact members 10 is arranged to move at a speed which varies as a direct the installation. This contact member is designed to be maintained in an initial position, which is determined by the engagement of the contact with a fixed stop 11,-

until the rate of flow of current in the installation exceeds a predetermined amount. This will be more fully described hereinafter. The second movable contact member 12 1s arranged to move toward and in the path of movement of the contact member 10. The extent of movement of the contact member 12 from its initial position is designed to be some direct function of the instantaneous rate of flow of current in the installation. The distance which the movable contact member 10 moves before enging with the contact member 12 is, thereore, an inverse measure of the instantaneous rate of flow. of current in the installation.

The movable contacts 10 and 12 are arranged to be actuated by an electric meter element operatively connected to the installation. The electric meter element shown in the drawings is of the well known induction type and comprises magnetizing coils 13 and 14. The coils 13 are arranged to be connected as potential coils across the conductors of the installation, and the coil 14 is connected as a current coil in series relation with the installation. The coils l3 and 14 produce, in the well understood manner,

a gear member 17. Damping magnets 18,

of the usual type, are operatively related to the disk 15 to render the speed of rotation of the disk direct? proportional to the rate of consumption 0 energy in the installation.

The movable contact member 10 is rigidly secured to a shaft 19 which is pivoted at one end to a stationary part of the relay.

The other end of the shaft 19 is mounted in a movable pivot 20. The pivot 20 is operacontrol spring 24: is operatively connected.

to the shaft 19 and tends to maintain the contact member 10 normally in engagement with the fixed stop 11. The spring 24 is included in the electric circuit 9 and electrically connects a conductor of this circuit to the movable contact 10.

A. second armature disk 25 is also arranged within the influence of the magnetic field produced by the coils 13 and 14. Damping magnets 26 of the usual type are operatively related to the armature 25. The armature is rigidly secured to. a pivoted shaft 27, and a control spring 28 is operatively connected to the shaft to render the extent of movement of the armature 25 a measure of the strength of the magnetic field produced by the coils 13 and 14, and hence a measure of the instantaneous rate of flow of current in the installation.

The movable contact member 12v is secured to a pivoted shaft 29. A pinion 30 is secured to this shaft and is adapted to mesh with a gear member 31 on the upper end of the shaft 27. A movement of the armature 25 thus produces a corresponding movement of the contact 12. A light hair spring 32 is connected to the shaft 29 and serves to flexibly and electrically connect conductor 9 to contact member 12.

A stationary contact 33 and a movable spring contact 34 are coiiperatively arranged in the electric circuit of the windings of electromagnets 22. A lug 35 is secured to the shaft 27 and operates to hold the movable contact 34 disengaged from contact 33 until the strength of the magnetic field produced by the coils 13 and 14 exceeds a predetermined amount. The tension of the spring 28 may be adjusted so as to restrain the movement of the armature 25 until the strength of the magnetic field produced by the magnetizing coils exceeds the predetermined amount, or the contacts 33 and 34 and the lug 35 may be so related that the contacts are maintained in-a disengaged position until the disk armature 25 has turned through a predetermined angle.

The operation of my improved and novel construction of relay will, it is believed, be understood from the foregoing description. It will be seen that the armature 15 constitutes in effect the rotating element of a watthour meter of the induction type, while the armature 25 constitutes in effect the movable element of an indicating Wattmeter of the same type. The speed of rotation of the armature 15 is, therefore, proportional to the rate of consumption of energy in the circuit breaking device illustrated in the.

drawings. The engagement of the movable contacts 10 and 12 completes the electric circuit and trips thecircuit breakerin thfi 4 usual manner. As long as the rate of flow of current in the installation is less than the predetermined amount, the relay remains inoperative. When the rate of How of current exceeds this predetermined amount, the contacts 33 and 34 are permitted to engage, and the electromagnets 22 are thereby energized. The movement of the armature 21 places the pinion 23 in engagement with the gear 17, and the movable contact.10 is thereupon rotated by the armature 15. The speed at which the contact 10 moves obviously varies with the rate of flow of current in the installation. moves from its initial position toward and in the path of movement of the contact 10 a distance which is a function of the instantaneous rate of flow of current in the installation. Accordingly the greater this rate of flow of current, the nearer the contact 12 will move toward the initial position of the contact 10. Furthermore, the greater the rate of flow of current, the faster will the contact 10 move toward the contact 12. It will thus be seen that both the contact 10 and the contact 12. impart to the relay an inverse time limit characteristic.

If at any time before the contacts 10 and 12 engage, the rate of flow of current in the installation 'falls below the predetermined rate, the contacts 33 and 34: will be disen gaged, and the electromagnets 22 deenergized. The pinion 23 will thereupon be operatively disconnected from the gear 17, and the contact 10 will return to its initial position responding to the influence of the spring 24. The relay is thereby restored to its initial position and is in readiness to again protect the translating devices from abnormal overloads. It will, furthermore, be seen that as soon as the circuit protecting device 5 has been operated that the actuating elements of the relay are automatically returned to their initial position, and the relay is again in readiness for connection in the protective device.

. For the purpose of illustration, I have explained the principle of my invention in connection with a watthour meter element,- and an indicating Wattmeter element ofthe induction type. It will, of course, be understood that my invention may be carried out with wattmeter elements of any other desired type, and furthermore that my invention in itsbroadest aspect is not limited to The contact 12.

electric wattmeter elements, but -contemplates the use of other measuring elements of electrical characteristics.

What I claim as new and desire to secure by Letters Patent of the United States, is

1. The combination with an electrical installation, of a relay comprising electromagnetic means electrically connected to the installation and adapted to roduce amagnetic field proportional to t e rate of flow of current in said installation, an armature rotatubl mounted in said .magnetic field, a move le member adapted to be operatively connected to said armature when the rate of flow of current in the installation exceeds a predetermined amount, a second movable member arranged to move toward and in the path of movement of said first mentioned member, a second armature movably mounted in said magnetic field, means operatively connecting said second armature to said second movable member, means for rendering the extent of movement of said second movable member a measure of the rate of flow of current in the installation when the rate of flow of current exceeds said predetermined amount and means controlled by the engagementoi said movable members for interrupting the flow of current in said installation.

2. A relay comprising in combination an electric meter element for producing a magnetic field, a rotatable armature mounted in said magnetic field, a movable member adapted to be moved by said armature when the strength of the magnetic field exceeds a predetermined amount, a second armature also mounted in said magnetic field, and a second movable member arranged in the path of movement of said first mentioned movable member and adapted to be moved by said second armature toward said first mentioned movable member a distance which is a function of the strength of the magnetic field.

3. A relay comprising in combination an electric meter element for producing a magnetic field, a rotatable armature mounted 1n said magnetic field, a movable member adapted to be moved by said armature when the strength of the' magnetic field exceeds a predetermined amount, a second armature also mounted in said magnetic field means for restraining the movement of said second armature until the strength of the magnetic field exceeds said redetermined amount, and a second mova 1e member adapted to be moved toward said first mentioned movable member by said second armature.

4. A relay comprising in combination an electric meter element for producing a magnetic field, a rotatable armature mounted In said magnetic field, a movable member adapted to be moved by said armature when the strength of the magnetic field exceeds a predetermined amount, a second armature also mounted in said magnetic field a control spring connected to said secon armature to render its movement a measure of the strength of the magnetic field, a sec ond movable member arranged to move toward and in the path of movement of said 6.'A relay comprising in combination an electric energy motor meter element and an indicating electric meter element, an electric circult, a movable contact in said circuit, a second movable contact in said circuit arranged to move toward and in the path of movement of said'first mentioned movable contact, means operatively connecting said second movable contact to said indicating meter element, and means controlled by said indicating meter element for operatively connecting said first mentioned movable contact to said energy meter element. A

7. A relay comprising in combination an electric energy motor meter element and an indicating electric meter element, a movable member adapted to be operatively connected to said energy meter element, means for restraining the movement of said indicating meter element until the torque tending to turn said element exceeds a prede termined amount, a second movable member arranged to move toward and in the path of movement of said first mentioned movable member, means operatively connecting said second movable member to said indicating meter element, and means controlled by said indicating meter element foroperatively connecting said first mentioned movable member to said energy meter element.

8. A relay comprising in combination an electric meter element for producing a magnetic field, a rotatable armature mounted in said magnetic field, an electric circuit, amovable contact in said circuit, a second movablefcontact in said circuit arranged to move toward and in the path of movement of said first mentioned movablecontact, a second armature also mounted in said magnetic field, a control sprin connected to said second armature to ren er its movement a measure of the strength of the magnetic field, means operatively connecting said second armature to said second movable contact, and means controlled by said second armature for operatively connecting said first mentioned movable contact to said first mentioned armature.

9. A relay comprising in combination an electric meter element for producing a mag netic field, a rotatable armature mounted in said magnetic field, an electric circuit, a movable contact in said circuit, means for operatively connecting said contact to said armature when the strength of the magnetic,

field exceeds a redetermined amount, a second armature a so mounted in said magnetic field, a control spring operatively connected to said armature, a second movable contact in said circuit and arranged to move toward and in the path of movement of said first mentioned contact, and means operatively connectin said second armature to said second mova 1e contact. v

10. A relay comprisin in combination an electric energy motor meter element and an indicating electric meter element, an electric circuit, a movable contact in said circuit,

means for operatively connecting said contact to said energy meter element when the torque tending to turn said energy meter element exceeds a predetermined amount, a second movable contact in said circuit arranged to move toward and in the path of movement of said first mentioned movable contact, and means operatively connecting I tact to an initial position, a second movable contact in said circuit arranged to move toward and in the path of movement of said first mentioned movable contact, a second armature mounted in said magnetic field, a control spring operatively connected to said second armature to render its movement a measure of the strength of the magnetic field, means operatively connecting said second armature to said second movable contact, and means controlled by said second armature for operatively connecting said first mentioned movable contact to said first mentioned armature when the torque tending to turn said second armature'exceeds a predetermined amount.

12. A relay comprising in combination an electric meter element for producing a magnetic field, a rotatable armature mounted in said magnetic field, a gear driven by said armature, an electric circuit, a movable conmeter armature also mounted'in said magnetic'field, a control spring operatively connected to said second meter armature and adjusted to restrain the movement of the armature until the strength of the magnetic field exceeds a predetermined amount, a second movable contact in said circuit arranged to move toward and in the path of movement of said first mentioned contact, means operatively connecting said second meter armature to said second movable contact, and contacts included in the circuit of the windin of said electromagnet and adapted to e closed when the strength of the magnetic field exceeds said predetermined amount.

13. The combination with an electrical installation, of a relay comprising an electric meter element for producing a magnetic field, a rotatable armature mounted in said magnetic field, a movable member adapted to be moved by said armature when the strength of the magnetic field exceeds a predetermined amount, a second armature also mounted in said magnetic field, means for rendering the extent of movement of said second armature a measure of the strength of the magnetic field, a second movable member adapted to be moved toward and in the path of movement of said first mentioned movable member by said second armature, and means controlled by the engagement of said members for interrupting the flow of current in said installation.

14. The combination withan electrical installation, of a relay comprising an electric energy motor meter element and an indicating electric meter element, a movable member adapted to be operatively connected to the energy meter element when the rate of flow ofcurrent in said installation exceeds a predetermined amount, a second movable member arranged to move toward and in the path of movement of said first mentioned movable member, means operatively connecting said second movable member to said indicating meter element, and means controlled by the engagement of said members for interrupting the flow of current in said installation.

15. The combination with an electrical installation, of a relay comprising an electric meter element for producing a magnetic field, a rotatable armature mounted in said magnetic field, a movable member adapted to be moved by said armature when the strength of.the magnetic field exceeds a predetermined amount, a second armature also mounted in said magnetic field, means for restraining the movement of said second artoward said first mentioned movable mem-' her by said second armature, and means actuated by the en agement of said members for interrupting tfie flow of current in said installation.

16. The combination with an electrical installation, of a relay comprising an electric meter element for producing a magnetic field, a rotatable armature mounted in said magnetic field, an electric circuit, a movable contact in said circuit, a second movable contact in said circuit arranged to move toward and in the path of movement of said first mentioned movable contact, a second armature also mounted in said magnetic field, a control spring connected to said second armature to render its movement a measure of the strength of the magnetic field, means operatively connecting said second armature to said second movable contact, means controlled by said second armature for operatively connecting said first mentioned movable contact to sald first mentioned armature, and means actuated by the engagement of said contacts for interrupting the flow of current in said installation.

17. The combination with an electrical installation, of a relay comprising an electric meter element for producing a magnetic field, a rotatable armature mounted in said magnetic field, an electric circuit, a movable contact in said circuit, means for operatively connecting said contact to said armature when the strength of the magnetic field exceeds a predetermined amount, a second armature also mounted in said magnetic field, a control spring operatively connected to said second armature, a second movable contact in said circuit and arranged to move toward and in the path of movement of said first mentioned contact, means operatively connecting said second armature to said second movable contact, and means actuated by the engagement of said contacts-for interrupting the flow of current in said installation.

18. The combination with an electrical installation including a circuit breaker, of an inverse time limit relay comprising an electric circuit, a movable contact in said circuit, electromagnetic means electrically connected to said installation and adapted to produce a magnetic field proportional to the rate of [low of current in the installation, an armature rotatably mounted in said magnetic field, a second movable contact in said circuit arranged to move toward and in the path of movement of said first mentioned contact, a second armature movably mounted in said magnetic field, means operatively connecting said second armature to said second movable contact, means for restraining the movement of said second armature while the rate of llow of current in said installation is less than a predetermined amount and for rendering the movement of said armature a measure of the rate of flow of current when the rate of flow of current exceeds said predetermined amount, means for operatively connecting said first mentioned armature to said first mentioned contact when the rate of flow of current exceeds the predetermined amount, and means actuated by the engagement of said contacts for operating said circuit breaker.

19. The combination with an electrical installation, of a relay comprising an electric circuit, electromagnetic means electrically connected to the installation and adapted to produce a magnetic field pro portional to the rate of flow of current in said installation, an armature rotatably -mounted in said magnetic field, a movable contact in said circuit adapted to be operatively connected to said armature when the rate of flow of current in the installation exceeds a predetermined amount, a second movable contact in said circuit arranged in the path of movement of said first mentioned contact, a second armature movably mounted in said magnetic field, means for rendering the extent of movement of said second contact a measure of the rate of flow of current in the installation when the rate of flow of current exceeds said predetermined amount, and means operated by the engagement of said contacts for interrupting the [low of current in said installation.

In witness whereof, I have hereunto set my hand this 23rd day of June, 1913.

\ JOHN THOS. DEMPSTER.

Witnesses BENJAMIN B. HULL, IIELEN Onrono. 

